JPS6141481B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to the preservation of green plant tissue, and more specifically to a solution and method for preserving the natural green color of flowers, stems, shrubs, trees, etc. It is related to. [Prior Art] The preservation of flowers and other plants as specimens in museums for the education of the natural sciences, as well as for decoration and exhibition purposes elsewhere, has been practiced for a long time. It has been practiced for many years, and many such preservation methods have been disclosed in the literature.
In particular, U.S. Pat.
No. 2,698,809 (invention by Mr. Huesendel) and US Pat.
(Hndbook of Plastic Embedding), written by E. C. Lutsuk (published in 1969), pages 60 to 73 are worth noting as they describe prior art methods of preserving plant and animal tissues. All of these known art preservation methods are completely inadequate.
This is because the pale natural color of flowers and other plant tissues tends to fade relatively quickly, and the stored product is very fragile, weak and susceptible to damage at extremes of temperature or humidity.
The green parts of plants contain chlorophyll, which is particularly difficult to treat because it is highly reactive and tends to become non-green (usually brown or brown). In fact, it is probably true that conventionally it has been stated that it is impossible to preserve the tissues of natural green plants. 6, 1978 under the title of "Plant tissue preservation solution and method for preserving plant tissue using this preservation solution" which is a related invention of the present invention.
Japanese Patent Application No. 53-73673, filed on May 1, 1983 (inventors Romero-Sheila and Webb, same applicant as the present inventor) discloses a treatment solution capable of treating flower specimens and the like. Although this solution treats virtually all colors very effectively, it is unsuitable for treating the green parts of plants, such as leaves, stems, etc. In addition, the related Canadian application discloses that the green parts of plants, leaves, etc. can be preserved in a substantially natural manner by a method similar to that used for flowers. has been done. However, even in this case, the processing solution and processing mechanism are complicated. [Problems to be Solved by the Present Invention] The present invention can be suitably used for many types of green plants, and can produce natural colored specimens without the need for special processing and storage techniques. The object of the present invention is to provide a preservation solution for green plant tissue that can maintain freshness, flexibility, and aesthetic appearance for a long period of time, and a method for preserving the same. [Means for solving the problem] According to one aspect of the present invention, at least a preservative component selected from the group consisting of water, at least a monohydric alcohol, a lower carboxylic acid, and a dihydric alcohol and a trihydric alcohol. and a buffer and mordant sufficient to adjust the PH and osmolality to permanently preserve the natural green color of the natural green plant tissue. According to a preferred embodiment of the invention, the natural green plant tissue preservation solution consists (per liter) of the following amounts of the compounds: Namely: 300-600 ml of water 200-400 ml of ethyl alcohol 20-60 ml of ethylene golycol 0-7 ml of glycerol 50-100 ml of propionic acid 50-75 g of citric acid 0.5-2.5 g of cupric sulfate 3-6 g of sulfuric acid Magnesium 6 to 12 g of sodium sulfite According to another aspect of the invention, water, at least a monohydric alcohol, at least a preservative component selected from the group consisting of lower carboxylic acids and dihydric and trihydric alcohols, and a natural green color. The plant tissue is placed in a natural green plant tissue preservation solution consisting of a buffer and a mordant sufficient to adjust the pH and osmolality to permanently preserve the natural green color in the plant tissue. A method for preserving natural green plant tissue is provided, which biologically preserves and fixes the green color in the tissue by immersion for a time sufficient to exchange naturally occurring water with the solution. In a preferred embodiment of the invention, the treated plant tissue is then soaked in an auxiliary solution of glycerol and water for at least 10 days and allowed to air dry. EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples. The subject matter of the present invention is (a) green preservation and (b) protection of processed specimens. Plant leaves and the like are made flexible when used for educational and botanical displays, and relatively rigid so that they can be freely erected when displayed in museums. While preserving flowers and the like is a relatively simple matter, as disclosed in related applications, preserving green specimens is an entirely different matter. Previously, it has not been possible to retain the shape and color of green fleshy leaves and other relatively non-fibrous tissues. This is because the shape of plant tissue is maintained by two elements that work together. First, cellulose and similar materials are relatively rigid in the organization in which cells are arranged. However, cells only fully swell when immersed in water, and once they lose water they break down, making the tissue very heavy and the fibers unsupported. When this phenomenon occurs, the organization wilts. When the tissue is completely dry, it loses lubrication between the fibers and regains its rigidity. The dehydration process must occur completely before the plant tissue loses its physical support medium. Failure of this dehydration process results in depigmentation of plant tissues due to lack of form and chemical reactions. In flowers, chlorophyll is a highly reactive and sensitive substance, so it is possible to retain color more easily than in green leaves. Flower pigments are developed in a way that reflects light rather than absorbing it. In this case, the pigment is chemically inert compared to chlorophyll. Therefore, the problem is that dehydration must be done in such a way as to preserve the original color and shape and treat the tissue so that it continues. Plant cell walls are made up of fibers that have a very high capacity to absorb moisture. Absorption of moisture from the air follows the diffusion of water vapor molecules from the air along a moisture concentration gradient. This phenomenon is particularly explained by Huyts's law, which states that the diffusivity is a function of the water concentration in the tissue and the water concentration in the air. Going in the opposite direction of this phenomenon, i.e. when the plant tissue becomes drier and the air becomes more humid, the amount of water molecules increases. The ability to absorb water is called the "water level", and dry plant tissues have a very high "water level". As plant tissues absorb water, the water level decreases, so the amount of water retained in the tissues is a function of atmospheric humidity. Once a dried plant tissue absorbs water from the atmosphere, the ability of the fibers to hold relative positions in the cell walls decreases and the tissue breaks down. The onset of tissue disintegration due to water absorption may be caused by endogenous enzymatic reactions, direct chemical reactions, or exogenous organisms such as parasitic bacteria. Endogenous reactions are followed by rehydration as cellular integrity is lost through dehydration and membranes are disrupted. When rehydration occurs, cellular contents mix, enzymes diffuse considerably, and non-enzymatic chemical reactions occur. In the case of green leaves, the following chlorophyll derivatives have been disclosed (by Daley in 1971 under the title ``Methodology and Characterization of Lake Chlorophyll Diagenesis'').
(written in his doctoral thesis in philosophy at Queen's University in Kingston in 1999). (1) Pheophytin: Gray and colored, produced in a mild acid state when the central chelate magnesium atom is removed. (2) Eophorbid: Gray and colored, produced when chlorophyllide and sometimes pheophytin are made acidic. It is chemically different from chlorophyll because the central magnesium atom and phytol have been removed. (3) Chlorophyllide: green, produced in the presence of the enzyme chlorophyllase. It differs from chlorophyll because the phytol has been removed. (4) Others: Contains chlorophyll isomers and isomorphs. These latter two chlorophyll derivatives are oxidized modifications. This metamorphosis is green and the spectral analysis is identical, but
The chromatograms are different. Mr. Daley said, ``In the withered leaves of tall plants, a distinct form of heteromorphic chlorophyll is produced by the action of the oxidative enzyme system, and the _C12 hydrogen is replaced with a methoxy group. Once the converted chlorophyll is produced, it can be converted to the corresponding pheophytin, pheophorbide or chlorophyll...''. Retention of the natural green color of chlorophyll or chlorophyll derivative-containing plants, especially when these leaves are exposed to high intensity light and/or high humidity, drying and processing in microwave ovens,
Many experiments have been conducted using many types of approaches to problems such as immersion in numerous processing baths with little success. Such treatments are believed to have failed due to hydration problems that adversely affect chlorophyll and its derivatives in green tissues. We therefore approached these problems fundamentally differently and did not attempt to dehydrate the green tissue;
They attempted to replace the water naturally contained in green tissue with a treatment solution containing sufficient chemical treatment agents to preserve the green color biologically and to establish it under environmental conditions. The treatment solution consists of buffers and the like to control the harsh biological effects of the primary compound. It has thus been found that suitable treatment solutions for green plant tissues consist essentially of four groups of chemicals: (a) water; (b) exchange media; (c) preservatives; (d) buffers, mordants and modifiers; and (c) preservatives. (i) biological preservative; (ii) environmental fixing agent; Embodiments such as deionized water and the like are also effective. The "exchange medium" used in the present invention is usually one or more monohydric alcohols having 1 to 6 carbon atoms. It is known that such alcohols, especially ethyl alcohol, isopropyl alcohol and tert-butyl alcohol, have dehydrating properties. In the present invention, the alcohol or the selected mixture of alcohols dehydrates the natural water contained in the plant tissues and simultaneously replaces them by the compound-containing water of the inventive solution of said alcohol;
Tertiary butyl alcohol is very harsh and destroys leafy tissue, so it is usually used with the addition of a milder alcohol, such as 1-propanol. On the other hand, ethyl alcohol can be used alone. As mentioned above, the preservative component of the solution is of three broad types, firstly, lower carboxylic acids, such as formic acid, acetic acid or propionic acid, or mixtures thereof, are effective as biological or tissue preservatives. I know something. secondly, as an environmental fixative, i.e., giving “body” to the preserved tissue;
and dihydric alcohols, such as glycols, more specifically trihydric alcohols such as ethylene glycol or glycerol (1,2,3-propanetriol), or mixtures thereof, as agents imparting resistance to "weather". It has been found to be very effective. Third, although not a necessary component, it is usually desirable to include a biological retentive agent, the most common example of which is formalin, although other retentive agents can be used. The fourth group of chemicals is "buffers, mordants and moderators", which contain small amounts of citric acid, dibasic sodium phosphate, magnesium sulfate, cupric sulfate, chromium alum and sodium sulfite, and mixtures thereof. Become. The amount of each chemical required is determined by the type of leaves being treated, the "exchange medium" used and other factors. Certain chemicals appear to act as mordants;
Other chemicals act as buffers not only for pH but also for osmotic pressure molarity. Without limiting the invention, it has been found that best results are obtained when the pH of the treatment bath is maintained between 6 and 8, ie, substantially neutral. It is also possible to add other minor components as required. For example, small amounts of salicylic acid can be beneficial for natural color, and if mold and the like have grown on specimens, it may be beneficial to use a fungicide such as Zephiran® (benzalkonium chloride). I found out something. A particularly preferred treatment solution is (per liter)
300-600 ml water 200-400 ml ethyl alcohol 20-60 ml ethylene glycol 0-7 ml glycerol 50-100 ml propionic or formic acid 50-75 g citric acid 0.5-2.5 g cupric sulfate 3-6 g sulfuric acid Magnesium Consists of 6-12g of sodium sulfite. Other preferred treatment solutions are: 400-600 ml water 100-150 ml 1-propanol 100-150 ml tertiary butyl alcohol 25-50 ml formalin 120-160 ml ethylene glycol 20-40 ml acetic acid 50-100 ml propionic acid 5 ~ 10 g cupric sulfate 0.5-5 g salicylic acid 0.5-2.0 g chromium alum 1-10 drops Zephyran® or 500-700 ml water 80-150 ml sec-butyl alcohol 20-40 ml formalin 50 ~70 ml ethylene glycol 100-140 ml glycerol 30-60 ml acetic acid 50-70 ml propionic acid 1-5 g cupric sulfate 1-3 g magnesium sulfate 1-5 g dibasic sodium phosphate. The method for processing plant tissue is very simple. First, the processing solution is prepared by mixing the necessary chemicals, preferably in the order described below, and then immersing the specimen in the processing solution at room temperature for 10 days to 2 weeks, or longer depending on the specimen. and adjusted. For example, deciduous leaves take less time to process than evergreen leaves, and thicker, tougher leaves like holly require soaking for 30 days or more. For example, very thick leaves, such as rubber leaves, need to be soaked longer. Succulent leaves and very juicy seeds and leaves with small fibrous tissues (e.g. mustard), depending on the species or method of growth, are not susceptible to this treatment solution even if the exchange medium is chosen very carefully. Since it is difficult to balance the natural water exchange rate,
Processing according to the invention is somewhat difficult. Generally, when immersed in a treatment bath, the leaf color changes to a light green color, and then when the treatment solution replaces the natural water, the color returns to its "ideal" color and darkens with continued immersion. After processing in the processing solution, the specimens are air dried and stored for use as needed. Specimens treated in this manner are best used (for educational or similar purposes) after two to three weeks due to their tendency to dry out. If you wish to preserve the specimen for a later date (i.e. when using spring or summer leaves for use as teaching material in mid-winter) or for permanent display, further treatment with an "auxiliary solution" is necessary. This auxiliary solution preferably contains 100 to 700 g/l of water.
It is a glycerin aqueous solution consisting of ml of glycerin. Specimens are simply immersed and left in the auxiliary solution for 2 to 3 weeks at room temperature and then air dried. Specimens treated in this way retain their color and flexibility for more than a year. In some circumstances it is possible to permanently store the specimen in an auxiliary solution depending on the intended use. There is therefore no practical limit to the processing time with the auxiliary solution. Example 1 A series of stock solutions were prepared as described above by mixing distilled water, monohydric alcohol, preservatives and buffers, and the solutions listed in Table 1 were prepared by adding each component in the order as described in the table below. Maintain the pH of the solution in the range of 6 to 8 per liter of solution.

【table】

【table】

[Table] Example 2 Examples of the various types of green leaves listed in Table 2 below are:
The specimens were immersed in solutions A, B, C, and D in Example 1 at room temperature for 10 days to 2 weeks. After treatment, the leaves were kept in an auxiliary bath of 650 ml of white glylin in 100 ml of distilled water for 2 to 3 weeks, then removed, air-dried, and evaluated for color and flexibility. .

【table】

[Table] It is clear from Table 2 that solutions A and D are preferred because they tend to cause less burning and darkening on most green leaves, and solution A is most preferred. For solution B, there are blanks in many cases, probably due to the strong and rough dehydrating effect of tertiary butyl alcohol, which is strong even when taking into account the regulating effect of pupanol.
Solution C provides results intermediate between solutions A and B, as the sec-butyl alcohol is not as distinctly bitter as the tertiary-butyl alcohol. It will be appreciated that many modifications to the compositions and methods of the invention may be made by those skilled in the art without departing from the concept and scope of the invention. For example, it has been discovered that adding water and aliphatic alcohol to a mixture of the other ingredients of the composition is possible and yields excellent results. This is advantageous from a market development and transportation point of view since many compositions contain water and alcohol, and it is preferable to supply them appropriately and mix them with the appropriate packaging mixture of the remaining ingredients. It is. As mentioned above, glycerin softens and makes the leaves pliable, providing desirable properties for many purposes or end uses, but not necessarily necessary for permanent display, such as for museum display.
Thus, when using solutions A or D, it is desirable to reduce the content of the glycerol component or not use it at all.

Claims (1)

[Claims] 1. Water, a monohydric alcohol selected from ethyl alcohol, isopropyl alcohol, sec-butyl alcohol, tertiary-butyl alcohol, and 1-propanol, or a mixture thereof, and formic acid, acetic acid, or propionic acid, or a mixture thereof. and a dihydric or trihydric alcohol selected from ethylene glycol or glycerol to adjust the pH and osmolality to permanently maintain the natural green color in natural green plant tissues. Citric acid, cupric sulfate, magnesium sulfate, sodium sulfite, salicylic acid, dibasic sodium phosphate,
A preservation solution for natural green plant tissue consisting of a buffer and a mordant selected from chromium alum or mixtures thereof. 2 Water, a monohydric alcohol selected from ethyl alcohol, isopropyl alcohol, sec-butyl alcohol, tertiary-butyl alcohol and 1-propanol or mixtures thereof, and formic acid, acetic acid or propionic acid or mixtures thereof. a lower carboxylic acid, a dihydric or trihydric alcohol selected from ethylene glycol or glycerol, and sufficient to adjust the pH and osmolality to permanently maintain the natural green color in naturally green plant tissue. Citric acid, cupric sulfate, magnesium sulfate, sodium sulfite, salicylic acid, dibasic sodium phosphate,
Said plant tissue is placed in a natural green plant tissue preservation solution consisting of a buffer and a mordant selected from chromium alum or mixtures thereof, sufficient to exchange with said solution the water naturally contained in said plant tissue. A method for preserving natural green plant tissue, which comprises biologically preserving and fixing the green color in the tissue by soaking it for a period of time.